Nonnegative solutions of an indefinite sublinear Robin problem II: local and global exactness results

Positive Solutions for Perturbations of the Robin Eigenvalue Problem plus an Indefinite Potential

We study perturbations of the eigenvalue problem for the negative Laplacian plus an indefinite and unbounded potential and Robin boundary condition. First we consider the case of a sublinear perturbation and then of a superlinear perturbation. For the first case we show that for λ < λ̂1 (λ̂1 being the principal eigenvalue) there is one positive solution which is unique under additional conditions...

The Existence Results for Solutions of Indefinite Scalar Curvature Problem

In this paper, we consider the indefinite scalar curvature problem on R. We propose new conditions on the prescribing scalar curvature function such that the scalar curvature problem on R (similarly, on S ) has at least one solution. The key observation in our proof is that we use the bifurcation method to get a large solution and then after establishing the Harnack inequality for solutions nea...

An existence results on positive solutions for a reaction-diffusion model with logistics growth and indefinite weight

In this paper, using sub-supersolution argument, we prove an existence result on positive solution for an ecological model under certain conditions. It also describes the dynamics of the fish population with natural predation and constant yield harvesting. The assumptions are that the ecosystem is spatially homogeneous and the herbivore density is a constant which are valid assumptions for mana...

Global Knowledge, Local Solutions: Interest Rate and Monetary Policy

A Unified Approach to the Global Exactness of Penalty and Augmented Lagrangian Functions II: Extended Exactness